Enhancement: Reference phpunit.xsd as installed with composer

Author: localheinz

phpunit.xml.dist

@@ -2,15 +2,17 @@
 
 <!-- http://www.phpunit.de/manual/current/en/appendixes.configuration.html -->
 <phpunit
-    backupGlobals               = "false"
-    backupStaticAttributes      = "false"
-    colors                      = "true"
-    convertErrorsToExceptions   = "true"
-    convertNoticesToExceptions  = "true"
-    convertWarningsToExceptions = "true"
-    processIsolation            = "false"
-    stopOnFailure               = "false"
-    bootstrap                   = "vendor/autoload.php">
+    xmlns:xsi                     = "http://www.w3.org/2001/XMLSchema-instance"
+    xsi:noNamespaceSchemaLocation = "vendor/phpunit/phpunit/phpunit.xsd"
+    backupGlobals                 = "false"
+    backupStaticAttributes        = "false"
+    colors                        = "true"
+    convertErrorsToExceptions     = "true"
+    convertNoticesToExceptions    = "true"
+    convertWarningsToExceptions   = "true"
+    processIsolation              = "false"
+    stopOnFailure                 = "false"
+    bootstrap                     = "vendor/autoload.php">
 
     <testsuites>
         <testsuite name="Project Test Suite">